Tunnel RT60 & STI vs length.

By Peter Patrick

Dear All,

I’ve been having some fun modeling sound systems for Road Tunnels. Garnering the truth out of a model can be interesting even before adding in the noise of the traffic and the exhaust fans. The attached PDF shows something of the nature of RT60 and the exponential nature of the effect of acoustic treatments.  The only “Treatment” in the case of a road tunnel model is often the “absorber” at the ends – the open end itself where sound exits the tunnel as vehicles do and doesn’t come back.

Tunnel Length vs RT60